Bacteria of the Duodenum. 



9i 



represent the behavior of organisms to changes of density of sea 

 water, and that the differences in the behavior of these three 

 organisms can hardly be correlated with the differences in con- 

 centration of the sea water in which they normally live. 



61 (757) 



Variations in the amount of transformed atoxyl (trypanotoxyl) 

 produced by varying the strength of atoxyl incubated with 



blood. 



By B. T. Terry. 



[From the Laboratories of the Rockefeller Institute for Medical Re- 

 search, New York City.] 



A 10 per cent, solution of atoxyl in blood incubated for 1 to 3 

 hours at 37 0 C. is more than 10 times as toxic for Trypanosoma 

 brucei as a 1 per cent, solution in blood similarly incubated. To 

 avoid misleading results due to the transforming action of red 

 blood corpuscles upon unaltered atoxyl continuing after the dilu- 

 tions are made, immediately after incubation all red blood cor- 

 puscles should be removed by centrifugalization from the fluid 

 containing the transformed atoxyl. 



62 (758) 



Some observations on bacteria of the duodenum. 

 By W. J. MacNeal and A. F. Chace. 



[From the Laboratories of the New York Post-Graduate Medical 

 School and Hospital.] 



The duodenal tube was sterilized by boiling in water for ten 

 minutes and the lower end was covered with a tightly-fitting 

 gelatin capsule which had been soaked in alcohol for several days. 

 The gelatin capsule was finally coated with shellac and dried. 

 The tube was ordinarily given late at night and the sample of 

 fluid aspirated on the following morning, usually without any 

 food being taken in the interval. In a few cases the fluid was 

 obtained an hour after giving an Ewald test meal. 



